/* memoria.css */

/* Reseteo de márgenes y paddings */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Arial', sans-serif;
    background-color: #1a1a1a;
    color: #333;
    padding: 1px;
}

header {
    text-align: center;
    margin-bottom: 20px;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.user-info {
    display: flex;
    justify-content: space-around;
    margin: 15px 0;
    font-size: 1.2rem;
}

button {
    display: block;
    margin: 20px auto;
    padding: 10px 10px;
    font-size: 1.4rem;
    color: #fff;
    background-color: #007bff;
    border: none;
    border-radius: 15px;
    cursor: pointer;
}

button:hover {
    background-color: #0056b3;
}

.tarjetas-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 5px;
    max-width: 300px;
    margin: 0 auto;
}

.tarjeta {
    position: relative;
    width: 100px;
    height: 100px;
    perspective: 1000px;
    cursor: pointer;
}

.tarjeta-frente,
.tarjeta-dorso {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 10px;
}

.tarjeta-frente {
    background-color: #777;
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    font-size: 5em;
}

.tarjeta-dorso {
    background-size: cover;
    background-position: center;
    transform: rotateY(180deg);
}

.tarjeta.flip .tarjeta-frente {
    transform: rotateY(180deg);
}

.tarjeta.flip .tarjeta-dorso {
    transform: rotateY(0);
}